In computer networks in general and telecommunication networks in particular, the term “policy” typically refers to a collection of one or more rules that govern the behavior of devices operating within the network as well as the network traffic that these devices generate. A policy charging and rules function (PCRF) is an entity that uses network operator-defined service policies, subscription information, and other data to make policy decisions. A PCRF may aid network operators in making real-time, subscriber-specific policy decisions to provide varying levels of quality of service (QoS). As a central policy decision point for a network, a PCRF node may instruct, control, manage, or inform one or more policy enforcement points, which are entities within the network that enforce the policy decisions made by the PCRF. One entity that enforces a policy with regard to a device or its traffic is a policy and charging enforcement function, or PCEF. Another entity that enforces a policy with regard to a device or its traffic is a bearer binding and event reporting function, or BBERF.
One challenge for a PCRF node is that the PCRF node may need to communicate with and control different policy enforcement points that may be of different types and may have different capabilities.
For example, policy enforcement may be performed at different levels in the network protocol. For example, so-called layer 3-4 enforcement includes enforcing policies based on the source or destination of the message, while layer 7 or application layer enforcement involves determining the type of message or the type of application that sent the message and enforcing policies based on that information. A PCRF may receive layer 3-4 information from one type of policy enforcement point and receive layer 7 information from another type of policy enforcement point.
Furthermore, some enforcement points may be “subscriber aware”, i.e., they know the identity of the subscriber associated with the device or traffic at issue, while other enforcement points may be “subscriber agnostic”, i.e., they do not know the identity of the subscriber associated with the device or traffic at issue. For example, enforcement points that are involved with the process of granting users access to the network are generally subscriber aware, since they generally need to authenticate and authorize users to the network. In contrast, subscriber agnostic enforcement points may make decisions based on source or destination addresses or based on message type without concern for subscriber identity or subscriber profile. A PCRF may receive from one type of policy enforcement point information that is subscriber aware (i.e., that includes information identifying a subscriber) and receive from another type of policy enforcement point subscriber agnostic information (i.e., that does not identify a particular subscriber.)
In addition, a PCRF may communicate with nodes that are not policy enforcement points, i.e., nodes that do not enforce a policy, but that provide valuable information which the PCRF may use to make policy decisions. Yet another challenge for a PCRF is that policy enforcement points and other nodes may use different types of communications link or different communications protocols, such as Gx, Gxx, and Rx, to name a few. Thus, a PCRF may need to communicate information to and from different types of sources via different protocols.
An additional challenge for the PCRF is that the PCRF may need to correlate the information that it receives from one source with information that it receives from a second source, where the two sources are of different types, have different capabilities, use different communications protocols, have different functions (e.g., policy enforcement points versus non policy enforcement points), or perform the same function but at different levels (e.g., layer 3-4 enforcement versus layer 7 enforcement.)
Accordingly, in light of these disadvantages associated with enforcement correlation or enforcement leg binding, there exists a need for network entities, methods, and computer readable media for policy enforcement correlation.